Conveying and mixing apparatus



June 1, 1943. R, M, COOK 2,320,509

CONVEYING AND MIXING APPARATUS 3 Sheets-Sheet 1 floaz/Pr/M 600K,

INVENTOR BY ZWQM ATTORN EY June 1, 1943. R. M. COOK CONVEYING AND MIXING APPARATUS Filed July 50, 1940 3 Sheets-Sheet 2 O F o 4.

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INVENTOR 9 ca f ATTORNEY June 1, 1943. R. M. COOK 2,320,509

CONVEYING AND MIXING APPARATUS Filed July so, 1940 s Sheets-Sheet s yazi azmx Patented June 1, 1943 UNITED STATES EPA'E'ENT QFEFICE mesne assignments,- to International menters, Inc., a corporation of Delaware Application July 30, 1940, Serial No. 348,426

5 Claims. (Cl. 259-164.)

This invention relates generally to mixing apparatus, and more particularly to improved apparatus for preparing a cementitious mixture and delivering it to a well during oil well cementing operations.

A principal object of the invention is to provide a system and apparatus of the foregoing type which facilitates the handling of the dry ingredients of the mixture and reduces the manual labor involved.

A more specific object is to provide, in conjunc-' tion with apparatus for mixing cementitious material, a novel and improved means for delivering dry ingredients in a steady stream to the mixing apparatus from a suitable source, either in bulk or packaged form, with a minimum of manual portable mixing and pumping apparatus for use in cementing oil wells and including power-operated pumps, a power-operated mixer, and an independently controllable power-operated conveyor for delivering dry ingredients to the mixer, and in which the controls for the various power-operated devices are within easy reach of a single operator from his station.

Other objects and advantages will be apparent from the following detailed description of a preferred embodiment of the invention, reference being had to the accompanying drawings where- Fig. 1 is a plan view of a complete oil well cementing equipment and illustrating the disposition of the mixer and its feeding conveyor with respect to the cementing truck and to a stack of sacks of cement;

Fig. 2 is a plan view of the mixer and conveyor and illustrating schematically one form of fluid transmission for driving the conveyor;

Fig. 3 is a view in side elevation of the mixer and conveyor;

Fig. 4 is an end View of the conveyor hopper; and

Fig. 5 is an enlarged vertical sectional view of the mixer and a portion of the conveyor.

Preparatory to cementing a string of casing in an oil well, the required number of sacks of cement are stacked near the well, and portable mixing and pumping equipment is set up at a convenient location close to the stack of sacked cement. The cementing operation is a continuous one during which the cement slurry is mixed and pumped down the well on the inside of the well casing and then upwardly in the annular space between the casing and the wall of the well. The volume of cement required depends, of course, on the length and diameter of the casing, and varies from less than a hundred sacks to upwards of two thousand sacks. The time element is of major importance because of the necessity of forcing the cement slurry to its final destination before setting takes place, and hence the slurry must be mixed at a rate which greatly exceeds that which is customary in other cementing operations such as construction work. Portable cement mixers now in use in oil well cementing operations are capable of mixing as many as forty sacks (forty cubic feet) of cement per minute.

In large scale cementing operations involving the mixing of from 500 to 2000 sacks of cement at a rapid rate, the problem of delivering the dry cement to the mixer has heretofore been a difficult one, and has necessitated the employment of from 6 to 20 men solely to carry the sacks of cement from the stack to the hopper of the mixer, in addition to the regular drilling crew and the cementers. The principal cause of the excessive manual labor involved is the fact that the mixer hopper is stationary and cannot be disposed in a single position within easy reach of all of the sacks of cement in a large stack. We have overcome this difficulty by providing a mixer having a feeding conveyor pivotally mounted thereon for horizontal swinging movement, whereby the loading end of the conveyor may be moved through an arc of substantial radius while the mixer is in operation. By stacking the sacks of cement in a substantially arcuate stack, and by setting up the mixer with the pivotal axis of the conveyor at the center of the arc, the loading end of the conveyor may be kept within easy reach of the sacks of cement throughout the entire operation by shifting the conveyor about its pivot from time to time.

Referring to Fig. 1 of the drawings, reference numeral I designates generally a cementing truck of conventional design, embodying a pair of pumps 2 and 3 and a pair of internal combustion engines 4 and 5 operatively connected to the pumps and having suitable controls mounted on a control panel 6 located adjacent the operators station on the truck. The pumps are connected by suction lines 1 to a receptacle 8 into which the cement slurry is discharged from the mixer 9, and a discharge line it) extends from the pumps to the inlet of the well. Suitable cross-connections (not shown) are usually provided for compounding the pumps in series or in parallel.

A Water supply tank 12 is mounted on the rear portion of the truck chassis, and is connected to the mixer 9 through a gravity feed line 13, the rate of flow of water to the mixer being controlled by a valve l4.

The mixer 9 is adapted to be mounted on the ground alongside the truck, and is preferably driven by the truck motor through a drive chain l9 engaging a driven sprocket 23 on the mixer (Figs. 3 and 5) and a power take-off sprocket (not shown) on the truck. As shown most clearly in Fig. 5, the mixer comprises an upright cylindrical chamber 22 having a closed bottom wall 23 and a detachable cover 24. The driven sprocket '20 is keyed to the outer ,end of a transverse shaft 25 journaled in a gear housing 26 attached to the under side of the base of the chamber, and a bevel pinion 27 is keyed to the inner end of the shaft. An upright shaft 23 extends through a central opening in the base, and has a bevel gear 29 keyed to its lower end and meshing with the pinion 21,

In order to seal the shaft opening in the base and to provide bearing support for the upper end of the shaft 28, a stationary sleeve 32 is rigidly secured to the base and extends upwardly around the shaft to a point above the maximum normal height of the liquid mixture in the chamber. A bearing bushing 33 is mounted in the upper portion of the sleeve and forms a bearing support for the upper end of the shaft. A second sleeve 34 is attached at its upper end to the upper end of the shaft 28, and extends downwardly around the stationary sleeve 32. A lower bearing bushing 35 is mounted in the sleeve 34 and engages the outer wall of the stationary sleeve 32 to rotatably support the lower end of the rotating sleeve. A plurality of blades 35 are secured to the sleeve 34 to rotate therewith, and are preferably inclined with respect to their planes of rotation in order to thoroughly mix the wet and dry ingredients introduced into the chamber.

A relatively large central opening is formed in the cover 24 for the reception of, a funnel 40. In the illustrated embodiment, the funnel is rotatably mounted in the mixing chamber about a vertical axis, and for this purpose a radially extending flange 4| is formed on the intermediate portion of the funnel and is loosely confined within an inwardly opening annular groove formed between the upper surface of the cover 24 and an undercut annular plate 42 detachably secured to the cover.

A pair of slots 45 and 46 (Figs. 3 and 5) are formed in diametrically opposite sides of the funnel, extending downwardly from its upper extremity and forming a cradle support for a pair of trunnions 41 and 48 extending radially outwardly from opposite sides of a cylindrical conveyor housing 49. As shown most clearly in Fig. 3, the upper portion of the funnel is cut away at 50 and 5| to conform substantially to the contour of the conveyor housing and thus form a substantially dust-tight joint between the funnel and the conveyor housing while permitting limited pivotal movement of the conveyor housing about the axis of the trunnions 41 and 48. As indicated in dotted lines in Fig. l, the conveyor housing 49 is swingable into difierent angularly related positions about the vertical axis of the mixing chamber, and the trunnion support of the housing on the funnel 40 enables the housing to tilt vertically on the trunnions to compensate for inequalities of the ground surface.

Referring to Figs. 2, 3 and 4, it will be observed that the conveyor housing 49 is inclined downwardly and outwardly from the mixing chamber, and terminates in an enlarged hopper 55 having upwardly flaring walls defining a storage chamber of substantial capacity. In order to facilitate the horizontal swinging movement of the conveyor about the axis of the mixing chamber, the hopper 55 is mounted on groundengaging wheels. As shown most clearly in Fig. 4, a transversely extending chassis 55 is secured to the hopper by suitable brackets 51', 53 and 59. Caster wheels 60, 6! are swivelly mounted at opposite ends of the chassis, and thus permit the outer end of the conveyor to be moved arcuately over the ground in either direction. The caster mounting of the wheels also aids in manipulating the conveyor during assembly and dismantiing of the apparatus in the field.

A screw conveyor extends through the conveyor housing 49 and comprises a continuous helical conveyor blade 65 formed integral with a shaft 66. The latter is journaled at its lower end in a combined radial and thrust bearing 5! (Figs. 3 and 4) and at its upper end in aradial bearing 58 (Fig. 5). The conveyor screw has a relatively close running clearance in the housing in order to function as a positive-displacement metering conveyor, whereby the rate of delivery of cement or other dry cementitious material may be contrcllably varied by varying the speed of rotation of the conveyor. As shown in Fig. 5, a discharge opening 69 is formed in the under side of the housing 48 in registry with the funnel 40, for discharging the material from the upper end of the housing through the funnel and into the mixing chamber. An inspection opening 10 is formed in the upper side of the housing 49 opposite the discharge opening, to permit an operator to observe conditions within the mixer during operation thereof. The inspection opening is normally closed by a pair of closure plates ll pivotally mounted on the housing.

As stated previously, the paddle shaft 28 of the mixer is driven from the motor of the cementing truck through a power take-off. The horsepower rating of the motor greatly exceeds that required to operate the mixer, and in the interest of efficiency and economy of operation it is preferable that at least a portion of the excess power available in the truck motor be utilized to operate the conveyor shaft 66. In the present instance, a simple and eflicient power transmission connection is provided between a power takeoff on the truck and the screw conveyor shaft, which enables the downwardly inclined shaft to be driven in all of its angularly adjusted positions about the vertical axis of the mixer.

As shown in Fig. 5, a reduced cylindrical extension sleeve 15 is provided on the upper extremity of the conveyor housing 49, over which is telescoped an extension sleeve 16 secured to a gear housing 71. A stub shaft 18 is journaled atone end in the gear housing, and is coupled in drivmg relation with the conveyor shaft 66 at. its other end. The gear housing 11 encloses a spur gear '19 keyed to the stub shaft 18 and an intermeshing pinion secured to the driven shaft of a fluid-operated motor 8!. For purpose of illustratlon We have shown the motor 8| as of the intermeshing gear type, but it will be understood that any other positively driven fluid motor would be equally suitable.

A fluid drive for the conveyor shaft 66 has the following distinct advantages over a mechanical drive-(1) the motor element of the fluid drive may be connected to a source of fluid under pressure by means of flexible hose connections which permit a wide range of movement of the motor relative to the source of motive liquid, and (2) the delivery of motive liquid from the pump to the motor can be readily varied within a wide range while the pump is driven at a constant speed, thereby varying the speed of the conveyor at will, independently of the speed of the prime mover or other source of power for driving the pump.

In Fig. 2 we have shown a hydraulic system for supplying fluid under pressure to the motor 8| to operate the motor at any desired speed and in either direction while the pump continues to operate at constant speed in one direction. For illustrative purposes, the pump, indicated at 85, is shown as a constant-volume pump, regulating means being interposed between the pump and the motor 8| for regulating the delivery of pressure liquid to the motor. It will be understood, however, that the pump may, if desired, be of the variable delivery type, of which there are several well-known makes available. In that case, the separate regulating means would obviously be dispensed with.

In the hydraulic system shown in Fig. 2, a storage reservoir 99 is connected to the inlet of the pump 85 by a supply conduit 81, and a delivery conduit 88 leads from the outlet of the pump to the inlet of a volume control and pressure regulating device schematically indicated at 89. Inasmuch as this device is of a well-known commercial type, a description thereof is deemed unnecessary except to state that it comprises generally a manually adjustable pressure regulating valve for automatically maintaining the pressure of the fluid delivered to the motor Bl at a predetermined value, and a manually adjustable by-pass valve for diverting any desired proportion of the output of the pump 85 back to the reservoir 89 through a by-pass conduit 99 and thereby varying the rate of delivery of fluid to the motor 8i through the delivery conduit 9|.

The by-pass valve may be adjusted by means of a dialed knob 92 having suitable indicia thereon to indicate to the operator the rate of flow to the motor. A four-Way directional control valve 93 is interposed between the conduit 9| and the motor BI, and is connected to the latter by two flexible conduits 94 and 95 which selectively serve as supply and exhaust conduits, depending on the setting of the valve 93. A return conduit 96 extends from the valve 93 back to the reservoir 86 for returning exhaust fluid from the motor. The valve 93 is provided with a manually operable lever 91 which is adjustable into either of two operating positions to selectively connect the delivery conduit 9| with either one of the flexible conduits 94 and 95 and to connect the other flexible conduit with the return conduit 96, to operate the motor 8| in either direction, or to a neutral position wherein the delivery conduit Si is cut off from both conduits 94 and 95 and the entire output of the pump is returned to the reservoir through the conduit 96.

It will be understood that the illustration of the hydraulic system in Fig. 2 is merely schematic, both as to the physical form and the location of the various devices comprising the system. In Fig, 1 the reservoir 86, pump 85, vol ume control valve 89, and directional control valve 93 are shown diagrammatically as mounted on the cementing truck, and are preferably located adjacent the operators station on the truck. The pump is provided with a drive sprocket 98 adapted to be connected by a drive chain to a power take-01f sprocket (not shown) on the truck, which in turn is connected in driving relation with the truck motor. It will be recalled that the paddle shaft 28 of the mixer 9 is also driven by the truck motor through the sprocket 2!], drive chain [9, and a power take-oil sprocket on the truck, and thus it is seen that the conveyor shaft 66 and the paddle shaft are driven from a common source of power, and that by adjustin the output of the fluid delivery end of the hydraulic transmission the speed of the conveyor shaft may be suitably varied to vary the consistency of the cement slurry without affecting the speed of the paddle shaft of the mixer.

Referring once again to Fig. 1, it will be observed that a cutter board I0! is detachably secured to the outer edge of the conveyor feed hopper 55. A sack cutter I92, usually in the form of a rotatable disk having sharpened teeth extending radially from its periphery, is provided in or adjacent to the hopper 55. During the mixing operation an operator stands at each side of the cutter board HM and they jointly slide the sacks of cement along the board from its outer end toward the hopper, the sack being slit open as it passes over the cutter I02. It will be obvious that with the sacks stacked in a substantially arcuate pile concentric with the vertical pivotal axis of the conveyor, the outer end of the cutter board may be positioned within easy reach of all of the sacks by periodically shifting the conveyor and hopper about its axis, as indicated by the dotted line positions in Fig. 1. Hence no steps need be taken to transfer the sacks from the pile to the cutter board, and one or two men can perform this operation whereas heretofore it has required from six to twenty men to carry the sacks to a stationary cutter board.

From the foregoing detailed description of one embodiment of the invention, it will be apparent that the manual labor involved in handling the sacks of cement has been materially reduced, and the entire operation has thereby been speeded up. It will also be apparent that by the provision of a variable speed hydraulic drive between the prime mover and the conveyor, the speed of the conveyor may be varied at will to feed the cementitious material to the mixer at any desired rate and thereby control the consistency of the mixed slurry within very close limits. The hydraulic drive including flexible conduits connecting the motor end of the drive with the pressure generating end also provides a simple and convenient means for maintaining driving connection between the stationary prime mover and the horizontally swim-gable conveyor in all adjusted positions of the latter.

The novel conveying and mixing apparatus described herein also facilitates the handling of cement or other dry ingredient from a source in other than sacked form-such, for instance, as from containers for bulk cement. It is within the contemplation of this invention that the cement, instead of being sacked in the usual manner, be in bulk form in storage hoppers or in wheel-mounted tanks of the trailer type. In either of the latter cases, the hoppers or tanks are arranged at the site of the cementing operation with their discharge spouts in an arc corresponding to the arcuate row of cement sacks in Fig. l of the drawings, but of slightiy smaller radius so that the hopper 55 may be selectively positioned under each of the discharge spouts in succession. In this manner, as each hopper or tank is emptied the conveyor 49 and hopper 55 may be swung about pivot to the discharge spout of the adjacent hopper or tank. The hopper 55 may be of sufficient capacity to hold a reserve supply of cement to feed the conveyor While it is being shifted, and consequently the shift can be effected without interrupting the continuous flow of cement to the mixing chamher. As stated previously, this is of utmost importance in cementing an oil well.

t is to be understood that the invention is not limited to the precise details of the embodiment illustrated and described herein, and that Various modification may be made therein within the spirit of the invention and the scope of the appended claims.

I claim:

1. Apparatus for mixing cementitious material for oil well cementing operations and the like, comprising: a stationary mixing chamber having a mixing element operable therein; means for supplying liquid ingredient thereto; means for supplying dry cementitious material to the mixing chamber comprising a conveyor frame hav ing the delivery end thereof swivelly communicating with the mixing chamber, a hopper secured to the receiving end of the conveyor frame and having an outlet communicating therewith, said hopper and conveyor frame being movable in a horizontal arc about a vertical axis adjacent the delivery end of the conveyor frame; power-operated conveyor means in said conveyor frame for transferring dry cementitlous material through said frame from said hopper to said mixing chamber; stationary drive means; and flexible driving connections between said drive means and said conveyor means for driving the latter in any horizontally adjusted position thereof with respect to said mixing chamber and drive means.

2. A cement mixer comprising: a mixing cham her having a mixing element operable therein and an inlet opening in its upper surface; a funnel member journaled in said opening for rotation relative to said chamber about a substantially upright axis, said funnel member having a portion extending upwardly from the upper surface of said mixing chamber and provided with substantially horizontally extending trunnion support at opposite sides thereof; a conveyor housing having a pair of trunnions extending from opposite sides thereof adjacent the discharge end thereof and engaging said trunnion supports; and a conveyor operable in said conveyor housing.

3. In a cement mixer, the combination of: a mixing chamber having a mixing element operable therein and an inlet opening in the upper portion thereof, a funnel member mounted in said opening for rotation relative to said chamher about a substantially upright axis, and conveyor means mounted on said funnel member for pivotal movement relative thereto about a substantially horizontal axis.

4. Portable apparatus for mixing and delivering cementitious material toa well or the like comprising, in combination: a motor vehicle; a cement mixer adapted to be mounted adjacent said vehicle and having a mixing element onerable therein; a driving connection between the vehicle motor and said mixing element; a cement pump mounted on said vehicle and having a suction inlet connected to the discharge outlet of said mixer and having a discharge outlet connected to a delivery point; drive means for said cement pump mounted on said vehicle and having manually operable speed control means accessible from an operators station on said vehicle; a water supply tank mounted on said vehicle and having a Water supply conduit connected to said mixer; manually operabl regulating means in said supply conduit accessible from said operators station; conveyor means for delivering cementitious material from a source to said mixer; and a variable speed hydraulic driving connection from said vehicle motor to said conveyor means and comprising a pump mounted on said vehicle and driven by said vehicle motor, a fluid motor operatively connected to said conveyor means, a fluid connection for delivering operating fluid from said last-named pump to said fluid motor, and control means for varying the delivery of operating fluid from said last-named. pump to said fund motor, said lastnamed control means being accessible from said operators station on the vehicle, thereby enabling a single operator to independently vary the speed of said conveyor means and the rate of delivery of Water to said mixer to thereby control the consistency of the mixed slurry, and to correlate the speed of the cement pump to the speed of the mixing operation.

5. Apparatus for mixing cementitious material for oil Well operations and the like, comprising: a mixing chamber supported in a fixed position and having an opening for receiving dry material, a conveyor housing swivelly and tiltably mounted with its delivery end registering with said opening, and with its receiving end terminating in a hopper; screw conveying means in said conveyor housing, and wheels supporting said receiving end for axial movement about the axis of the opening to said mixing chamber.

ROBERT M. COOK. 

